Well, let's end this discussion... I'll add optional support for additional formats in the future, but I can't promise by when (given the many things on the TODO list and the limited time I have right now). Until then, please convert your images to PNGs smile.

On Linux/UNIX I'd suggest ImageMagick's 'convert' for this, which is easily scriptable. And Anna gave an example for Windows.

A mind is like a parachute. It doesn't work unless it's open. [Frank Zappa]